The invention concerns a reactor and its use, for example for carrying the controlled oxidation reaction of an oxidizable charge by an oxidizing gas or a mixture of gases containing at least one oxidizing gas, that is to say, a gas permitting oxidation of said charge.
The invention applies more particularly to oxidation, preferably slow and usually partial oxidation, of oxidizable charges such as hydrocarbons, with a view to the preparation of synthesising gas essentially comprising carbon monoxide and hydrogen, for synthesis e.g. of methanol and/or higher homologous alcohols, and ammonia.
Although the oxidizing gases may in particular be oxygen, ozone or halogens, only oxidation reactions with oxygen will be considered, as examples, in this specification.
It is known to carry out partial oxidation of methane as indicated, for example, in U.S. Pat. No. 2,621,117.
According to the specification of that U.S. patent, the reaction takes place in a flame where the gases are never perfectly mixed. Under these conditions high temperatures are reached rapidly in the zones rich in oxygen. The high temperature gases are then mixed with most of the hydrocarbon charge to be oxidized, and cause cracking of molecules and carbon formation, which is very troublesome for the remainder of the process. If it is important to operate under economic conditions, that is to say, particularly without having to use excess oxygen, a dust removal stage then has to be provided as taught particularly in recent U.S. Pat. No. 4,699,631, before the gases formed are used at the oxidation stage.
It is also known that oxidation reactions may be carried out using the flame pinching concept. The principle is well known and is described, e.g. in the book by G. de Soete and A. Feugier "Physical and Chemical Aspects of Combustion" Editions TECHNIP pages 87 to 93. The wall effect is used to reduce the reaction speed and avoid propagation of the flame resulting from combustion.
In processes using the flame pinching concept the presence of oxygen, which may be pure or diluted with inert gases, and the high temperature, involving a strong heat flux, make it necessary to have flame stopping means to enable the reaction to continue without explosion, although one is usually within explosive limits (particularly in the case of partial oxidation of methane).
Several recent patents or patent applications have been based on this principle. Those in Applicants' name can be cited in particular: EP-B-221813, EP-B-231706 and FR 2628727 and U.S. Pat. No. 3,467,504.